Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
  • H02P9/14—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field
  • H02P9/36—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field using armature-reaction-excited machines
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
  • H02P9/14—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field
  • H02P9/26—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field using discharge tubes or semiconductor devices
  • H02P9/30—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field using discharge tubes or semiconductor devices using semiconductor devices
  • H02P9/302—Brushless excitation
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
  • H02P9/14—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field
  • H02P9/32—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field using magnetic devices with controllable degree of saturation

Definitions

• the present invention generally relates to the production of a mono- or polyphase alternating current, for example three-phase, by means of an alternator, the latter comprising a rotor driven in rotation by a heat engine for example, and more particularly the control such alternators.
• An alternator comprises, in known manner, an exciter inductor winding supplied with variable current so as to generate an exciter armature winding, which is then rectified by a rectifier bridge to supply the rectified current to the rectifier armature. winding main inductor of an alternator. This avoids the presence of rings and brushes between the rotating part and the fixed part of the alternator.
• the control of the alternator is traditionally carried out by means of a voltage regulator detecting variations in the output voltage of the alternator, which may be due to a variation of the load applied to the alternator.
• the regulator modifies the current flowing in the exciter field winding according to a control loop of the output voltage of the alternator.
• the response time of the control loop can be relatively large, in particular because of the response time of the voltage regulator and the electrical and mechanical time constants of the exciter and the alternator.
• US Pat. No. 3,656,051 and US Pat. No. 4,453,120 disclose alternators comprising a rotary control circuit arranged between the exciter armature winding and the main generator inductor winding, this control circuit being configured to maintain the output voltage of the alternator at a predetermined level by controlling the current in the alternator rotor in response to a control signal received from a comparison circuit.
• alternators comprise inductors with inductor with permanent magnets or having a winding powered by a battery.
• alternators have the disadvantage of a cost and a size of the exciter relatively important, especially for permanent magnet exciters, or dependence on a battery and its charging system.
• Patent Application EP-A1-0 233 425 also discloses a device for regulating an alternator without rings or brushes in which the supply circuit of the excitation inductor winding comprises auxiliary windings, intended to collect the fundamental voltage and the third harmonic voltage of the alternator, and a regulator of the excitation current, controlled on the one hand as a function of the fundamental and third harmonic voltages and, on the other hand, the output voltage of the alternator.
• the exciter field winding is supplied with variable current by the voltage regulator, which can cause delays in the alternator response and higher transient voltage variations.
• the current variation in the exciter inductor winding is delayed by the time constant of this inductor. The voltage variation across the alternator that results is greater than it would be without exciter.
• the invention aims to meet all or part of the aforementioned needs.
• an alternator stator comprising: a main winding of an armature delivering an output voltage
• an alternator rotor comprising:
• an alternator configured to maintain the amplitude of the output voltage of the alternator at a predetermined level by controlling the supply of the rotating inductor winding in response to a control signal from the alternator voltage regulator, the auxiliary winding (s) generating a voltage due to their exposure to a magnetic field generated by the rotating inductor winding.
• an alternator stator comprising:
• a main winding of an armature delivering an output voltage, at least one auxiliary winding,
• an alternator rotor comprising: an exciter armature winding, and
• the exciter inductor winding is not powered by a battery and furthermore is different from a permanent magnet inductor, thereby reducing the cost of the alternator.
• the power supply of the exciter inductor winding is non-dependent on the main armature winding and in particular the output voltage of the alternator, in particular because the power supply of the exciter inductor winding is not controlled by the voltage regulator.
• the use of auxiliary windings to the stator provides the excitation voltage of the exciter.
• the exciter inductor winding is fed through the auxiliary winding (s), which provide sufficient power supply under all operating conditions of the alternator.
• the invention can also allow a faster regulation, since the control of the excitation current of the rotating inductor winding reduces the delay due to the exciter.
• the exciter field winding can be supplied with direct current by the auxiliary winding (s).
• the alternator may comprise several auxiliary windings, for example two.
• the control circuit may comprise a rectifier, for example a rectifier bridge, for transforming the alternating voltage of the exciter armature winding into a rectified voltage for supplying the rotating inductor winding.
• the control device may include an electronic switch between the rotating inductor winding and the exciter armature winding, which is controlled according to the control signal.
• the electronic switch can for example be a static component.
• the control circuit may be arranged to control the electronic switch according to a pulse width modulation.
• the control circuit may include a freewheeling diode across the rotating inductor winding.
• the voltage regulator may comprise a digital processing unit, arranged to monitor the output voltage of the alternator and to generate the control signal according to the output voltage, in particular the frequency, the frequency integral and of the derivative of the frequency of the output voltage and the amplitude of the integral and the derivative of the amplitude of the output voltage.
• the control signal may be transmitted from the voltage regulator to the control circuit by inductive connection, in particular a low frequency link, by an optical link, in particular by infrared, or by emission of electromagnetic waves, in particular high frequency or very high frequency.
• the alternator may comprise at least one rectifier for rectifying an alternating voltage generated by at least one auxiliary winding into a rectified voltage supplying the exciter field winding. The rectified voltage can also supply the voltage regulator.
• the exciter inductor winding can be powered in pulse width modulation so as to limit the current in the exciter inductor winding.
• the output voltage of the main winding of the stator can be three-phase.
• the invention also relates to a generator comprising an alternator as defined above.
• the generator may for example further comprise a heat engine.
• FIG. 1 schematically represents an alternator produced in accordance with FIG. to the invention.
• the alternator 1 represented in FIG. 1 comprises an alternator stator 2 comprising a stator armature main winding 7 delivering an output voltage, for example a three-phase voltage, the three phases being designated U, V, W.
• Each phase may comprise one or more windings.
• the stator 2 also comprises auxiliary windings 3 whose role will be described later.
• the alternator further comprises an alternator rotor 8 comprising a rotating inductor winding 4 disposed on the shaft of the machine, the shaft being for example driven by an engine not shown.
• the auxiliary windings 3 generate a voltage due to their exposure to a variable magnetic field generated by the rotating inductor winding and the stator armature reaction.
• the alternator 1 comprises an exciter comprising on the one hand a fixed exciter inductor winding 5, powered by the auxiliary windings 3 and on the other hand an induced exciter winding 6.
• the rotating inductor winding 4 is energized by the exciter armature winding 6 through a control circuit 10 configured to maintain the amplitude of the alternator output voltage at a level predetermined by controlling the supply of the rotating inductor winding in response to a control signal from a voltage regulator of the alternator.
• the alternator comprises two auxiliary windings 3 to the stator.
• the exciter inductor winding 5 may be powered by a rectified voltage from the auxiliary windings 3, for example by means of a rectifier 21.
• the latter may comprise two single-phase rectifier bridges 22 arranged in parallel with the rectified side, each associated with an auxiliary winding 3.
• the rectifier 21 may comprise a current limiting system 23, for example of the pulse width modulation type, using one or more static switches, for example IGBT transistors. .
• a freewheeling diode 27 is connected to the terminals of the exciter inductor winding 5.
• the current limiting system has the role of setting an excitation cap and thus reducing the thermal drift due to heating of the exciter inductor winding.
• This excitation cap may for example be adjustable.
• the excitation current to be supplied varies according to the fundamental and third harmonic voltages generated in the auxiliary windings 3 and is limited to an adjustable ceiling.
• the current limiter system 23 and the voltage regulator 20 may for example be located in the same housing.
• the voltage regulator 20 can be powered by the rectified voltage at the output of the rectifier 21.
• the voltage regulator 20 generates a control signal which is transmitted from the stator 2 to the rotor 8 and then processed in the control circuit 10 to control the excitation current of the rotating inductor winding 4.
• the voltage regulator 20 comprises, for example, a digital processing unit 25 which can be arranged to monitor the output voltage of the alternator, for example between two phases, and to generate the control signal as a function of the output voltage and in particular the value of the frequency, the integral of the frequency, and the derivative of the frequency of the output voltage and the amplitude, the integral and the derivative of the amplitude of the output voltage .
• the digital processing unit 25 may be arranged to implement a proportional-integral-derivative type control strategy of the amplitude and the frequency of the output voltage signal subordinated to logical choices depending on the calculated values compared to reference levels.
• the digital processing unit 25 may for example comprise one or more logic circuits, for example one or more microprocessors or microcontrollers.
• control signal is transmitted from the fixed part of the alternator to the rotating part.
• the transmission can be done for example by an inductive link, or by emitting electromagnetic waves, or by optical link, including optoelectronic.
• control circuit 10 which is for example supplied by the exciter armature winding 6.
• the control circuit 10 may comprise a rectifier bridge 12 making it possible to transform the multiphase alternating current of the exciter armature winding 6 into a rectified current for supplying the rotating inductor winding 4.
• the control circuit 10 controls an electronic switch 11, which may comprise one or more components, for example at least one semiconductor electronic switch, for example an IGBT transistor.
• the control signal may comprise at least one information varying from a minimum to a maximum.
• the minimum corresponds for example to a zero current, the switch 11 being continuously open and the maximum can correspond to the switch 11 continuously closed.
• the control law of the switch 11 as a function of the control signal may not be linear.
• the electric switch 11 can be controlled according to a variable pulse width modulation mode.
• the control circuit 10 may for example comprise for this purpose a switching system 14 of pulse width modulation type.
• a freewheeling diode 15 may be connected to the terminals of the rotating inductor winding 4.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Control Of Eletrric Generators (AREA)

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• 2005
  • 2005-11-04 FR FR0511264A patent/FR2893200B1/fr not_active Expired - Lifetime
• 2006
  • 2006-10-24 WO PCT/FR2006/051101 patent/WO2007051939A2/fr not_active Ceased
  • 2006-10-24 EP EP06831293.3A patent/EP1952525B1/de not_active Not-in-force
  • 2006-10-24 CN CNA2006800479043A patent/CN101341649A/zh active Pending
  • 2006-10-24 US US12/084,125 patent/US8013578B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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